• U-1105 "Black Panther" German U-boat Sub
• U rigonne
• Čuf
• Ukumbe Reef
• Ullastre I
• Ullastre II
• Ullastres
• Ullastres Iii
• Ulong Channel
• Ulua Beach
• Ulysses, wreck
• Um Almaradem
• Um el Faroud
• Um el Faroud - Oil Tanker
• Um-faroud
• Um-faroud, Wied Iz-zurrieq (Sur)
• Um Khararim (Cave Reef)
• Um Sid
• Umm El Ros/Marsa Mubarak
• Umm Gamar
• Umm Usk
• Underwater Forest
• 潘家口水下长城underwater Great Wall
• Underwater Great Wall
• Underwater Military Museum
• Underwater Museum of the Arts
• Underwater Sculpture Park
• Underwater Triglav
• University - האוניברסיטה
• Unterwasserwald
• Unterwilen
• Upcoming Divespot Amersfoort
• Urisee
• Ursus (Wreck)
• USAT Liberty Wreck
• Uss Emmons
• Uss Oriskany
• USS Tucker
• Žusterna
• Utopia Beach House Reef South
• Uvala Polje - Zid
• Uvala Slana
• Uvala Zakenj